High densification of a semiconductor device has been attained by miniaturization of a size of a pattern. This miniaturization has been attained by a lithography technology, in particular, by shortening of wavelength of an exposure light source, but increasing in cost of an exposure device becomes a problem. A double patterning technology in which the pattern created by a conventional exposure device is further miniaturized has been studied, but processes are complicated, and therefore, an inexpensive miniaturization technology has been required.
Therefore, a technology using a block copolymer (BCP) in which plural kinds of polymer blocks are bonded has been studied to correspond to miniaturization of the pattern. The BCP is microphase-separated, aligned in a desired position and direction, and thereby, it is possible to process a substrate while using the above as a template (mask).
As a method to manufacture a line-and-space pattern being one of typical patterns of a semiconductor device, a method using a phase-separation structure of a lamellar or a cylinder from among the microphase-separation modes of the BCP is devised. In particular, a mask function with high aspect is expected for a lamellar structure compared to a cylinder structure. Accordingly, a method arranging the lamellar structure in a desired direction by using a physical guide and a chemical guide has been studied. In particular, according to the chemical guide method, it is possible to seamlessly align a self-assembled pattern at a whole of a desired area, and therefore, it is considered to be a useful method.
In this chemical guide method, it is necessary to form a line pattern whose affinity with one composition of a diblock copolymer is high at a desired line-and-space pattern creation area on the substrate.
At this time, it is necessary to set a width of the chemical guide to be ½ of a self-assembled phase-separation pitch to control a phase-separation alignment without any defect. To create the chemical guide, a conventional photolithography is used, but a most advanced lithography technology is necessary to create the fine chemical guide by using the photolithography, and it is difficult to correspond to further miniaturization request of 10 nm or less.
To avoid these problems, a method to widen the width of the chemical guide to be ½ or more of the self-assembled phase-separation pitch, is devised.
However, in this method, a substrate parallel alignment of lamellar is easy to be induced because a surface energy of the chemical guide is set to be the same as a surface energy of each polymer block in the block copolymer. Namely, reliability of the creation of the line-and-space pattern is lowered.